/*
 * This file is part of Applied Energistics 2. Copyright (c) 2013 - 2015, AlgorithmX2, All rights reserved. Applied
 * Energistics 2 is free software: you can redistribute it and/or modify it under the terms of the GNU Lesser General
 * Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any
 * later version. Applied Energistics 2 is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
 * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General
 * Public License for more details. You should have received a copy of the GNU Lesser General Public License along with
 * Applied Energistics 2. If not, see <http://www.gnu.org/licenses/lgpl>.
 */

package appeng.recipes.loader;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.InputStreamReader;

import javax.annotation.Nonnull;

import com.google.common.base.Preconditions;

import appeng.api.recipes.IRecipeLoader;

/**
 * Loads the recipes from the config folder
 */
public final class ConfigLoader implements IRecipeLoader {

    private final File generatedRecipesDir;
    private final File userRecipesDir;

    public ConfigLoader(final File generatedRecipesDir, final File userRecipesDir) {
        this.generatedRecipesDir = generatedRecipesDir;
        this.userRecipesDir = userRecipesDir;
    }

    @Override
    public BufferedReader getFile(@Nonnull final String relativeFilePath) throws Exception {
        Preconditions.checkNotNull(relativeFilePath);
        Preconditions.checkArgument(
                !relativeFilePath.isEmpty(),
                "Supplying an empty String will result creating a reader of a folder.");

        final File generatedFile = new File(this.generatedRecipesDir, relativeFilePath);
        final File userFile = new File(this.userRecipesDir, relativeFilePath);

        final File toBeLoaded = (userFile.exists() && userFile.isFile()) ? userFile : generatedFile;

        return new BufferedReader(new InputStreamReader(new FileInputStream(toBeLoaded), "UTF-8"));
    }
}
